![Figure 2. Measurement of biological parameters to model chromosome segregation. (A, left) Kymograph of a cen2-gfp (centromere [Cen] chromosome [Chr] II) and cdc11-gfp (SPB) cell showing the in vivo oscillation of chromosome II between the SPBs (Video 2). (right) Tracked trajectories of the fluorescence signals from Cen2-GFP and Cdc11-GFP shown on the left. (B) In vivo experiment. (left) Laser ablation of the spindle apparatus in a metaphase cdc25-22 cell expressing a fluorescent marker protein is shown on the left for the kinetochore (Kt; Ndc80-GFP, green) and the SPB (Cdc11-GFP, green). Note that metaphase spindles in this mutant strain are longer than in wild-type cells. The positions of one kinetochore pair (red circles) are followed after laser ablation (the laser pulse is located at the blue dot) as illustrated on the kymograph constructed from the cropping outlined in white in the image. (right) Graphic representation showing the distance between the pair of kinetochores after laser ablation (time 0 = time of laser impact). The red line represents the best fit of an exponential relaxation curve. (C) In silico simulation. (left) Kymograph showing the dynamics of all three kinetochore pairs on a metaphase spindle of similar length to a cdc25-22 cell after elimination of the force generators (simulated laser ablation, blue dot). (right) Comparison of kinetochore relaxation seen in vivo (red trace) with that seen by modeling in silico (blue trace). (D–F) Further comparison of parameters of mitosis determined in vivo and modeled in silico. (D) Kinetochore speed distribution obtained after tracking of kinetochores in vivo and in silico. (E) Spindle elongation rate distribution for the in vivo and in silico trajectories. (F) Comparison of the autocorrelation function (mathematical tool to determine a repeat pattern) used to determine the attachment rate as described in the Materials and methods. Red and blue arrowheads show first minima of the autocorrelation functions for the in vivo and in silico autocorrelation functions, respectively.](https://cdn.rupress.org/rup/content_public/journal/jcb/196/6/10.1083_jcb.201107124/6/jcb_201107124_fig2.jpeg?Expires=1767685930&Signature=vgdYrQffOxIVn114y3nfiZE1MyirR~Oz8I2YZjesTDn5c1Qn7uFiUW6A~nQbYFAMYJRnrZ2YHut79Eqp0ZTeGAwuSXlqMwEbJwZqjkLTogiBexeE7oa5kSooNin01Bx5jjqnnNJLveq8XM8aW9aQFEJi7oeLYglJJsXE-sm2ipGUkJG345xkBVSpcZPq0LygvKVo1gh2GB5jxJnMkkX08dhhfhb~Fpl4wBj~SDDwIhrCa24Mx6ZQdHfjbMaW13Ybmg9ldKy2iT2WuTKR2os042RKPICWuqll4McZti31Zsvh6QtkKdNSxS5NlL3an9Kh4fLTX4PSUb1cElTwqZ94lQ__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
Measurement of biological parameters to model chromosome segregation. (A, left) Kymograph of a cen2-gfp (centromere [Cen] chromosome [Chr] II) and cdc11-gfp (SPB) cell showing the in vivo oscillation of chromosome II between the SPBs (Video 2). (right) Tracked trajectories of the fluorescence signals from Cen2-GFP and Cdc11-GFP shown on the left. (B) In vivo experiment. (left) Laser ablation of the spindle apparatus in a metaphase cdc25-22 cell expressing a fluorescent marker protein is shown on the left for the kinetochore (Kt; Ndc80-GFP, green) and the SPB (Cdc11-GFP, green). Note that metaphase spindles in this mutant strain are longer than in wild-type cells. The positions of one kinetochore pair (red circles) are followed after laser ablation (the laser pulse is located at the blue dot) as illustrated on the kymograph constructed from the cropping outlined in white in the image. (right) Graphic representation showing the distance between the pair of kinetochores after laser ablation (time 0 = time of laser impact). The red line represents the best fit of an exponential relaxation curve. (C) In silico simulation. (left) Kymograph showing the dynamics of all three kinetochore pairs on a metaphase spindle of similar length to a cdc25-22 cell after elimination of the force generators (simulated laser ablation, blue dot). (right) Comparison of kinetochore relaxation seen in vivo (red trace) with that seen by modeling in silico (blue trace). (D–F) Further comparison of parameters of mitosis determined in vivo and modeled in silico. (D) Kinetochore speed distribution obtained after tracking of kinetochores in vivo and in silico. (E) Spindle elongation rate distribution for the in vivo and in silico trajectories. (F) Comparison of the autocorrelation function (mathematical tool to determine a repeat pattern) used to determine the attachment rate as described in the Materials and methods. Red and blue arrowheads show first minima of the autocorrelation functions for the in vivo and in silico autocorrelation functions, respectively.
